SCSNSCSN http://scsn-dev.gps.caltech.edu Southern California Seismic Network Mon, 24 Apr 2017 13:53:50 +0000 en-US hourly 1 https://wordpress.org/?v=4.7.2 04/23/2017, M3.4 event near Montecito ../../index.php/2017/04/23/04232017-m3-6-event-near-montecito/ ../../index.php/2017/04/23/04232017-m3-6-event-near-montecito/#respond Sun, 23 Apr 2017 18:14:03 +0000 http://scsn-dev.gps.caltech.edu/?p=2139 ]]>
  • 23 Apr 2017 10:55:55 PDT, (34.417, -119.647), depth 12.9km, 3km SSW of Montecito, California
  • Aftershocks: so far there has been 1 aftershock recorded, m3.1 at 11:56:01 PDT. Some may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%%) that a larger quake could occur, with the likelihood decreasing over time.
  • Historical seismicity: since our records began in 1932 we’ve had 5 events of M4 or greater within 10km of today’s event, the largest was M5.5 (1941/07/01) and the most recent was M4.1 on 10 Mar 1986.
  • Nearby faults: Mesa-Rincon Creek fault zone (Mesa-Rincon Creek fault) (1.4 km), Mission Ridge fault system, Mission Ridge section (Mission Ridge fault) (2.6 km), Red Mountain fault zone (Red Mountain fault, north branch) (3.0 km), Mission Ridge fault system, Arroyo Parida section (Fernalo Point fault) (3.4 km), Mesa-Rincon Creek fault zone (Mesa fault) (4.1 km), Mission Ridge fault system, Arroyo Parida section (Arroyo Parida fault) (4.2 km), Lavigia fault zone (Lavigia fault) (5.2 km), Lavigia fault zone (7.7 km), Santa Ynez fault zone, eastern section (8.5 km).
  • Links for: USGS earthquake page, ShakeMap, DYFI, waveforms.
  • Visit our special reports page for further information on local notable earthquakes.
  • ]]>
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    03/22/2017, M4.0 event near Alberto Oviedo Mota ../../index.php/2017/03/22/03222017-m4-0-event-near-alberto-oviedo-mota/ ../../index.php/2017/03/22/03222017-m4-0-event-near-alberto-oviedo-mota/#respond Wed, 22 Mar 2017 20:40:24 +0000 http://scsn-dev.gps.caltech.edu/?p=2112 ]]>
  • 22 Mar 2017 11:57:32 PDT, (32.225, -115.228), depth 18.5km, 6km W of Alberto Oviedo Mota, B.C., Mexico
  • Aftershocks: so far (22 Mar 2017, 01:26PM PDT) there has been 1 aftershock recorded, M3.8. More may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%) that a larger quake could occur, with the likelihood decreasing over time.
  • Historical seismicity: since our records began in 1932 we’ve had 93 events of M4 or greater within 10km of today’s event, the largest was M7.2 (2010/04/04) and the most recent was M4.1 on 17 Apr 2013.
  • Links for: USGS earthquake page, ShakeMap, DYFI, waveforms.
  • Visit our special reports page for further information on local notable earthquakes.
  • Below are the waveform data associated with this event, as recorded in our Live Seismograms Feed. The closest station shown here is CI.RXH, approximately 113 km from the epicenter.

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    03/14/2017, M3.6 event near Salton City ../../index.php/2017/03/14/03142017-m3-6-event-near-salton-city/ ../../index.php/2017/03/14/03142017-m3-6-event-near-salton-city/#respond Tue, 14 Mar 2017 17:24:04 +0000 http://scsn-dev.gps.caltech.edu/?p=2084 ]]>
  • 14 Mar 2017 10:14:05 PDT, (33.238, -116.053), depth 5.2km, 11km SW of Salton City, California
  • Aftershocks: so far there have been no aftershocks recorded. Some may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%%) that a larger quake could occur, with the likelihood decreasing over time.
  • Historical seismicity: since our records began in 1932 we’ve had 42 events of M4 or greater within 10km of today’s event, the largest was M6.6 (1968/04/09) and the most recent was M4.3 on 09 Feb 2007.
  • Nearby faults: San Jacinto fault zone, Anza section (Clark fault) (10.1 km), San Jacinto fault zone, Borrego Mountain section (Coyote Creek fault) (11.7 km) and San Jacinto fault zone, Coyote Creek section (Coyote Creek fault) (13.8 km).
  • Links for: USGS earthquake page, ShakeMap, DYFI, waveforms.
  • Visit our special reports page for further information on local notable earthquakes.
  • Below are the waveform data associated with this event, as recorded in our Live Seismograms Feed. The closest station shown here is CI.RXH, approximately 40 km from the epicenter, while the furthest stations (e.g. CI.VOG, CI.PHL) are over 450 km from the epicenter (no clear earthquake signal recorded).

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    03/13/2017, M3.6 event near Loma Linda ../../index.php/2017/03/14/03132017-m3-6-event-near-loma-linda/ ../../index.php/2017/03/14/03132017-m3-6-event-near-loma-linda/#respond Tue, 14 Mar 2017 05:33:37 +0000 http://scsn-dev.gps.caltech.edu/?p=2073 ]]>
  • 13 Mar 2017 22:06:54 PDT, (34.038, -117.238), depth 17.6km, 2km ESE of Loma Linda, California
  • Aftershocks: so far (14 Mar 2017, 08:25AM PDT) there have been 2 aftershocks recorded, the largest M0.9 (smallest M0.9). More may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%) that a larger quake could occur, with the likelihood decreasing over time.
  • There was 1 event during the 3 days prior to the earthquake (within a 15 km radius), with M0.9 (2017/03/12).
  • Historical seismicity: since our records began in 1932 we’ve had 12 events of M4 or greater within 10km of today’s event, the largest was M4.7 (1936/02/23) and the most recent was M4.1 on 13 Feb 2010.
  • Nearby faults: San Jacinto fault zone, San Bernardino section (Loma Linda fault) (0.2 km), Crafton Hills fault zone (Live Oak Canyon fault) (0.9 km), San Jacinto fault zone, San Bernardino section (Claremont fault) (1.4 km), San Jacinto fault zone, San Bernardino section (San Jacinto fault) (3.0 km), Crafton Hills fault zone (Redlands fault) (4.7 km), Crafton Hills fault zone (6.0 km), Crafton Hills fault zone (Reservoir Canyon fault) (6.6 km), San Jacinto fault zone, San Jacinto Valley section (8.7 km), San Jacinto fault zone.
  • Links for: USGS earthquake page, ShakeMap, DYFI.
  • Visit our special reports page for further information on local notable earthquakes.
  • Below are the waveform data associated with this event, as recorded in our Live Seismograms Feed. The closest station shown here is CI.RVR, approximately 13.5 km from the epicenter, while the furthest stations (e.g. CI.VOG, CI.PHL) are over 300 km from the epicenter.

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    03/01/2017, M3.5 event near Salton City ../../index.php/2017/03/01/03012017-m3-5-event-near-salton-city/ ../../index.php/2017/03/01/03012017-m3-5-event-near-salton-city/#respond Wed, 01 Mar 2017 20:43:34 +0000 http://scsn-dev.gps.caltech.edu/?p=2063 ]]>
  • 01 Mar 2017 12:18:39 PST, (33.135, -115.862), depth 11.5km, 20km SSE of Salton City, California
  • Aftershocks: so far (01 Mar 2017, 12:38PM PST) there has been 1 aftershock recorded, M2.3. More may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%) that a larger quake could occur, with the likelihood decreasing over time.
  • Historical seismicity: since our records began in 1932 we’ve had 29 events of M4 or greater within 10km of today’s event, the largest was M6.6 (1987/11/24) and the most recent was M4.1 on 19 Jul 1991.
  • Nearby faults: San Jacinto fault zone, Superstition Hills section (Kane Spring fault) (3.4 km), San Jacinto fault zone, Superstition Hills section (5.1 km)
  • Links for: USGS earthquake page, ShakeMap, DYFI.
  • Visit our special reports page for further information on local notable earthquakes.
  • Below is the waveform data associated with this event as recorded in our Live Seismograms Feed

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    12/31/2016, Swarm near Brawley (largest M3.9) ../../index.php/2017/01/03/12312016-swarm-near-brawley-largest-m3-9/ ../../index.php/2017/01/03/12312016-swarm-near-brawley-largest-m3-9/#respond Tue, 03 Jan 2017 17:10:03 +0000 http://scsn-dev.gps.caltech.edu/?p=1851 ]]>
  • A seismic swarm commenced on December 31st, 2016, near Brawley. So far there have been more than 250 events recorded.
  • The largest event in the swarm so far was a M3.9 on 31 Dec 2016 at 15:06:56 PST, (32.975, -115.545), depth 14.5km, 2km WSW of Brawley, California
  • 8 events over M3 have been recorded and more than 80 events over M2. More than 250 events over M0.5 have been recorded.
  • Cumulative number of events over time (top) and event magnitudes over time (bottom) for the swarm near Brawley.



    Map showing events in the swarm near Brawley coloured by time (blue early, red late) and sized by magnitude. The star marks the largest (M3.9) event in the cluster. Faults are shown as grey lines. Historical seismicity above M4.5 is marked by grey stars and magnitude values.


  • Historical seismicity: since our records began in 1932 we’ve had 22 events of M4 or greater within 10km of today’s event, the largest was M5.8 (1979/10/16) and the most recent was M4.2 on 28 Aug 2012.
  • Nearby faults: Imperial fault (3.9 km), Brawley seismic zone (Brawley fault zone) (6.7 km), San Jacinto fault zone, Superstition Hills section (Superstition Hills flt) (13.6 km) and San Jacinto fault zone, Superstition Hills section (Wienert fault) (14.3 km).
  • Links for: USGS earthquake page, ShakeMap, DYFI.
  • Visit our special reports page for further information on local notable earthquakes.
  • ]]>
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    12/28/2016, M4.0 event near Morongo Valley ../../index.php/2016/12/28/12282016-m4-0-event-near-morongo-valley/ ../../index.php/2016/12/28/12282016-m4-0-event-near-morongo-valley/#respond Wed, 28 Dec 2016 18:09:13 +0000 http://scsn-dev.gps.caltech.edu/?p=1846 ]]>
  • 28 Dec 2016 09:56:59 PST, (34.152, -116.707), depth 10.1km, 16km NW of Morongo Valley, California
  • Aftershocks: so far there have been 7 aftershocks recorded. More may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%) that a larger quake could occur, with the likelihood decreasing over time.
  • Historical seismicity: since our records began in 1932 we’ve had 2 events of M4 or greater within 10km of today’s event, the largest was M4.8 (30 Jun 1992).
  • Nearby faults: Santa Ana fault zone (Santa Ana fault) (4.2 km), Pinto Mountain fault zone (Pinto Mountain fault) (8.6 km), San Gorgonio Mountain fault (8.9 km), Helendale-South Lockhart fault zone, northern San Bernardino Mountains section (9.0 km), San Andreas fault zone, San Bernardino Mountains section (Mill Creek fault) (9.9 km), Pipes Canyon fault (10.3 km) and San Andreas fault zone, San Bernardino Mountains section (Mission Creek fault) (11.3 km).
  • Links for: USGS earthquake page, ShakeMap, DYFI.
  • Visit our special reports page for further information on local notable earthquakes.
  • ]]>
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    10/31/2016, M3.5 event near Niland ../../index.php/2016/10/31/10312016-m3-5-event-near-niland/ ../../index.php/2016/10/31/10312016-m3-5-event-near-niland/#respond Mon, 31 Oct 2016 16:48:02 +0000 http://scsn-dev.gps.caltech.edu/?p=1799 ]]>
  • 31 Oct 2016 03:41:07 PDT, (33.187, -115.567), depth 3.1km, 7km SW of Niland, California
  • This event is the largest so far in a small cluster of events that started at about 2:30am PDT, consisting of about 35 recorded events. A few events were also recorded in the same area on 26 Oct 2016. A smaller cluster of events also occurred on the 26 Oct 2016 about 3km to the west of the most recent seismicity, giving a total of approximately 50 events over the last 6 days. We have recorded 4 events over M3 and more than 20 events over M2.
  • Current cumulative event rate and magnitudes for the small swarm near Niland.

    NilandSwarmOct2016_rate

  • The events are in the southern section of the Brawley Seismic Zone, a relatively active area for seismicity. Swarms occur relatively frequently, notably the swarms that occurred during the 1970’s and 1980’s in this area made the zone among the most active areas in all of California.
  • Historical seismicity: since our records began in 1932 we’ve had 11 events of M4 or greater within 10km of today’s event, the largest was M5.1 (2005/09/02) and the most recent was M4.2 on 24 Dec 2014.
  • Relocated events for the small swarm near Niland, forming a very tight cluster. Figure provided by Egill Hauksson, Caltech.

    Niland_eqs_31-Oct-2016

    Catalogue events in the current small swarm near Niland coloured by time (blue early, red late) and sized by magnitude. Historic seismicity above M4.5 is marked by a grey star and the event’s magnitude.

    NilandSwarmOct2016_map

  • The following information comes from our special report on the 2005 Obsidian Butte swarm
    • The Brawley Seismic Zone is a north-striking zone of northwest and northeast-striking faults that extends from the southern end of the San Andreas fault to the northern end of the Imperial fault. It is often considered a remnant spreading center in the transition from the Gulf of California mid-ocean ridge to the San Andreas transform fault. Historically, activity includes both northeast-oriented cross-faults that typically involve left-lateral faulting, and activity on northerly to northwesterly-oriented strands (right-lateral faulting) of the zone. The largest events to have occurred on the cross-faults were the Elmore Ranch event in 1987, which is considered to have triggered the Superstition Hills event less than 12 hours later, and the Westmorland event in 1981. The Brawley Seismic Zone is proximal to the southern San Andreas fault, the San Jacinto fault zone, and the Imperial fault.
    • The pattern of Brawley swarms of the 1970’s was a large number of very small earthquakes (sometimes exceeding 10,000 events) with up to a dozen moderate events of magnitude 4 or so, but no clear mainshock larger than the other events. The 1970’s swarms would be highly active for a few days and then taper off over the next week or two.
  • Links for: USGS earthquake page, ShakeMap, DYFI.
  • Visit our special reports page for further information on local notable earthquakes.
  • ]]>
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    09/26/2016, M4.3 event near Bombay Beach ../../index.php/2016/09/26/09262016-m4-3-event-near-bombay-beach/ ../../index.php/2016/09/26/09262016-m4-3-event-near-bombay-beach/#respond Mon, 26 Sep 2016 15:18:21 +0000 http://scsn-dev.gps.caltech.edu/?p=1717 ]]>
  • These events are the largest so far in a swarm that started on 26 Sep 2016, 04:03AM PDT, and is occurring in the Brawley Seismic Zone near the southern terminus of the San Andreas Fault.
    • M4.3, 26 Sep 2016 07:31:08 PDT, (33.298, -115.713), depth 2.4km, 6km SSE of Bombay Beach, California
    • M4.3, 26 Sep 2016 20:23:58 PDT, (33.300, -115.712), depth 4.8km, 6km SSE of Bombay Beach, California
    • M4.1, 26 Sep 2016 20:36:15 PDT, (33.305, -115.702), depth 2.5km, 6km SSE of Bombay Beach, California
  • This swarm is noteworthy because it is happening near the southern terminus of the San Andreas Fault. This is the same are as the two previous swarms in this region, which occurred in 2009 and 2001. No swarms prior to 2001 with a M4.0 have been recorded in the area since 1933.
  • Events in the swarm show a NE-SW trend, consistent with the 2009 and 2001 swarms. This trend is in alignment with the faults located in the northern Brawley Seismic Zone, and orthogonal to the San Andreas fault. Before 2001, there were few events that had occurred in the northern Brawley Seismic Zone. The southern Brawley Seismic Zone is much more active, with events occurring on a regular basis. More information on the Brawley Seismic Zone and nearby faults can be found in the special report on the 2009 swarm.
  • The swarm includes more than 290 events so far (30 Sep 2016, 12:05PM PDT) in the magnitude range M0.7 to M4.3, there have been 17 events with magnitude greater than M3 and 97 events with magnitude greater than M2. The M4.3 exhibited strike-slip motion with one nodal plane at N47E, and the other sub-parallel to the strike of the San Andreas Fault. Relocations of these events show that the are located in the depth range 4 to 9 km.
    • The 2009 swarm had two large strike-slip events: M4.8 and M4.0.
    • The 2001 swarm had two large strike-slip events: M4.1 and M3.4.
    Relocated events for the Sep 2016 Brawley swarm.

    Brawley swarm 2016 relocations

    Relocated events for the Sep 2016 Brawley swarm shown with the swarms from 2001 and 2009.

    Brawley swarm 2016 relocations with 2001 and 2009 swarms

    Cumulative event rate for the Sep 2016 Brawley swarm.

    Brawley swarm 2016 rate

  • There were 4 events during the 3 days prior to the earthquake (within a 1 km radius), the largest was M3.3 (2016/09/26).
  • Historical seismicity: since our records began in 1932 we’ve had 8 events of M4 or greater within 10km of today’s event, the largest was M4.8 (2009/03/24) and the most recent was M4.8 on 24 Mar 2009.
  • Nearby faults: Brawley Seismic Zone faults (orthogonal to San Andreas fault), San Andreas fault zone, Coachella section (5.8 km) and Hot Springs fault (10.3 km).
  • Links for: USGS earthquake page, ShakeMap, DYFI.
  • Visit our special reports page for further information on local notable earthquakes.
  • ]]>
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    07/31/2016, M4.0 event near Westmorland ../../index.php/2016/08/02/07312016-m4-0-event-near-westmorland/ ../../index.php/2016/08/02/07312016-m4-0-event-near-westmorland/#respond Tue, 02 Aug 2016 20:29:46 +0000 http://scsn-dev.gps.caltech.edu/?p=1596 ]]>
  • 31 Jul 2016 09:21:05 PDT, (32.958, -115.760), depth 3.2km, 16km SW of Westmorland, California
  • Aftershocks: so far there have been no aftershocks recorded. Some may be expected in the next few days, the largest expected is approximately 1 magnitude unit smaller than the mainshock. There is a small chance (about 5%) that a larger quake could occur, with the likelihood decreasing over time.
  • There were 2 events during the 3 days prior to the earthquake (within a 1 km radius), the largest was M2.6 (2016/07/31).
  • Historical seismicity: since our records began in 1932 we’ve had 15 events of M4 or greater within 10km of today’s event, the largest was M6.6 (1942/10/21) and the most recent was M4.7 on 28 Jan 1988.
  • Nearby faults: Superstition Hills flt, 1.3 km; Superstition Mountain section fault, 3.7 km; Lone Tree fault, 8.3 km; Wienert fault, 9.9 km; East Elmore Ranch fault, 10.7 km; and Elmore Ranch fault, 10.8 km; all within the Superstition Hills section of the San Jacinto fault zone.
  • Links for: USGS earthquake page, ShakeMap, DYFI.
  • Visit our special reports page for further information on local notable earthquakes.
  • ]]>
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